The invention relates to breastshields used with breastpumps by nursing mothers.
Breastshields typically used in conjunction with breastpumps have a conical configuration and are usually funnel-shaped. The breastshield need not be conical, of course, but nonetheless will ordinarily have a part within which at least some of the breast is received along with the nipple. In use, the interior of the breastshield is placed against the nursing mother""s breast, and the breastpump extracts milk from the breast through application of a negative pressure (vacuum) within the breastshield. Breastpumps having breastshields of this type are shown and described in U.S. Pat. Nos. 4,929,229 and 4,857,05 1, for instance.
Breastshields typically have a funnel-shape, comprising a conical portion with a tubular extension, sometimes referred to as the nipple tunnel. The nipple and surrounding breast are received in the conical portion, with the nipple often extending into the tubular extension. Under vacuum, the breast is pulled further into the breastshield, ordinarily with the nipple then being pulled into the tubular extension, with the surrounding breast thereby also compressed about the nipple.
A nursing mother""s nipples may thus be forced against the wall of the nipple tunnel under vacuum. This may cause friction against the wall as the nipple moves deeper into the nipple tunnel. There can also be friction between the breast and the conical portion, as well as the nipple tunnel. This may result in irritation, particularly if the mother is already suffering from some topical problem, such as a chapped or cracked nipple condition. This makes the pumping of milk from the breast uncomfortable. If it were possible to reduce or eliminate the chafing and irritation of a nursing mother""s breast when a breastpump is used, an advance in the art would be afforded.
The invention comprises an improved breastshield for a breastpump having a breast-receiving portion which is provided with a lubricious surface. In one embodiment, it has bonded to its interior breast-contacting surface a coating of a polymeric lubricant, having a reduced coefficient of friction. The polymeric lubricant may preferably be from the group consisting of polytetrafluoroethylene, fluorinated ethylene-propylene copolymers, poly (vinylidine fluoride), polyparaxylene and silicone lubricant polymers. Preferred polymers of this group are the polyparaxylene polymers and the polytetrafluoroethylene polymers, with parylene being a presently preferred lubricating material. It is to be understood that any number of other well-known lubricating materials may be used in the practice of the invention, as will be made evident hereafter. Due to the particular application of the invention as a breast shield, it is necessary that the particular polymers chosen be acceptable for bodily contact.
While the lubricating material may be bonded directly to a rigid breast-receiving part of the breastshield, which could also be an insert or adaptor received in a breastshield, it is furthermore envisioned to provide the lubricious surface in conjunction with elastomeric materials making up a soft breast-receiving part. Whether a rigid or softer substrate is employed, the lubricating material can be provided as a coating to the already formed substrate (or base). Alternatively, the two layers could be molded together in the same molding operation, or in a two-shot type molding process, just to name two other applications.
In another embodiment, the lubricant polymer material is mixed with or otherwise contained within the substrate, to provide a relatively homogeneous lubricant-containing breastshield surface area.
Yet another variation of the foregoing embodiment has the lubricant material releasable upon contact with water, or heat. The lubricant may be encapsulated, for instance, and then released to coat the surface in use.
The foregoing objectives and advantages of the invention will be further understood upon consideration of the following detailed description of certain embodiments taken in conjunction with the drawings, in which: